It has long been known to release fire extinguishing fluid retained under pressure within a container by means of a shock wave generated through the medium of activation of an explosive squib. For example, see U.S. Pat. Nos. 3,491,783 and 3,552,495. As is noted in Patent 3,491,783 the squib is used to activate a knife which cuts a sealed diaphragm to thereby release the pressurized fluid whereas in U.S. Pat. No. 3,552,495, the diaphragm is broken by the shock wave directly. The present invention is directed to the latter type of concept and is an improvement thereover.
Under certain applications it has been found that a fire extinguisher reliant upon application of electrical current for activation of the explosive squib will sometimes fail if the electrical current source fails or, for some reason, the electrical circuit continuity is interrupted. It has therefore been determined that an alternative means for operating the fire extinguisher is desirable as a backup to thereby increase reliability of the fire extinguishing system.